Seat clamp



FIG. 1 is a front, top, left perspective view of the seat clamp of the new design;

FIG. 2 is a front elevational view thereof;

FIG. 3 is a top plan view thereof;

FIG. 4 is a left side view thereof;

FIG. 5 is a right side view thereof;

FIG. 6 is a bottom plan view thereof; and,

FIG. 7 is a back elevational view thereof. 

CLAIM The ornamental design for a seat clamp, substantially as shown and described. 